Ultrasonic Welding Simulations for Multiple Layers of Lithium Ion Battery Tabs

Abstract

Ultrasonic welding is a solidstate bond created using ultrasonic energy. It has been used in the semiconductor industry for several decades, and more recently, in the automotive industry such as for lithiumion battery welding. Although there existed numerical simulations for ultrasonic welding, the models were limited to twolayer and like materials stackups. In this study, finite element theories are introduced and simulation procedure is established for multiple sheets and dissimilar metal ultrasonic welding. The procedures require both abaqus/Standard and abaqus/Explicit to simulate the coupled mechanicalthermal phenomena over the entire weld duration with moderate computational cost. The procedure is verified and used to simulate selected specific cases involving multiple sheets and dissimilar materials, i.e., copper and aluminum. The simulation procedure demonstrates its capability to predict welding energy, distortion, and temperature distribution of the workpieces. Case studies of ultrasonic welding simulations for multiple layers of lithiumion battery tabs are presented. The prediction leads to several innovative ultrasonic welding process designs for improved welding quality.